Blast shows North Korean nuclear threat growing

SEOUL, South Korea 
North Korea's second underground nuclear test has shown the world that it's only a matter of time before the secretive regime develops the ability to mount an atomic weapon on a missile.

Monday's blast – by all accounts larger than its first one in 2006 – indicates the impoverished country will keep using its nuclear development in efforts to bolster its regime and raise its stature against its main perceived adversary, the United States. It has also raised fears of increased proliferation.

North Korea's defiance in carrying out the latest explosion, which followed its first test in October 2006 that resulted in censure and sanctions by the United Nations, has met widespread condemnation and cast more doubt over the prospects for stalled talks aimed at the country's denuclearization.

President Barack Obama said the blast and North Korea's test firings of short-range missiles off its coast "pose a grave threat to the peace and security of the world," while Pyongyang answered Tuesday by launching more missiles. And on Wednesday, the North warned South Korea and the United States that Seoul's decision this week to participate in a U.S.-led program to intercept ships suspected of carrying weapons of mass destruction is equal to a declaration of war.

North Korea is believed to have processed enough plutonium over the years to have enough fissile material for at least half a dozen nuclear bombs.

That is paltry compared to the massive arsenals of nuclear powers such as the United States, Russia and China or even newer members of the atomic club like Pakistan.

Still, Pyongyang is making measurable progress and showing its determination to posses a credible enough threat to protect its regime, and it is unlikely to back down anytime soon given its increasingly strident tone on the world stage.

The North is now "more of a threat because they have more data and information about their bomb design," said Daniel Pinkston, a Seoul-based analyst for the International Crisis Group, a Brussels-based think tank devoted to conflict resolution. "They're demonstrating this decisiveness."

The size of the explosion is still under debate and will require more analysis to determine its actual size. Initial estimates have placed it between a few kilotons to between 10 and 20 kilotons by Russia's Defense Ministry.

The latter range, considered way too high by analysts including Pinkston and David Albright, president of the Institute for Science and International Security in Washington, would be comparable to the weapons that destroyed the Japanese cities of Hiroshima and Nagasaki during World War II.

Evidence suggests Pyongyang's ultimate goal is to mount a nuclear warhead on a missile, but analysts vary in their assessment of how close the country is to reaching this goal.

"It's a weapons program aimed at putting something on a missile to create a credible deterrent," said Albright of the ISIS. He said he thinks North Korea has the ability to mount a weapon now, though he added that questions remain about how reliable it would be.

Yoon Deok-min, a professor at South Korea's state-run Institute of Foreign Affairs and National Security, said North Korea appears still to be in the process of mastering the miniaturization technology required to mount a warhead onto a missile, though he called its ultimate success just "a matter of time."